Regional Anaesthesia in the Critically Ill

OVERVIEW

• multiple techniques for various situations

ADVANTAGES

• reduced opioid to achieve analgesia – less respiratory depression, especially in chest injury or high risk of respiratory failure (elderly, COPD)
• laparotomy -> supreme analgesia, improved respiratory function (The MASTER trial), decrease in arrhythmias and acute coronary syndrome
• can be used to minimise opioid consumption and thus troublesome side effects (N+V, constipation, ileus with subsequent aspiration or enteral feed intolerance)
• less interference with mental status
• reduced used of non-opioids: NSAIDs -> renal impairment, platelet dysfunction, tramadol -> confusion in the elderly, ketamine -> hypertension, tachycardia, dissociative effects.

DISADVANTAGES

Patient and critical illness factors

• often redundant in sedated, ventilated patients
• not proven in critically-ill to better in terms of outcome -> not a lot of strong evidence to support its use
• may still need opioids
• difficult covering multiple sources of pain
• may alter signs in compartment syndrome
• monitoring of blockade in uncooperative patient maybe impossible
• removal with DVT prophylaxis may be an issue

Procedure factors

• technical expertise required
• need for patient positioning
• anatomical land-marks may be difficult

Complications

• related to placement (vascular injection, pneumothorax, neurological injury)
• LA toxicity risk (especially with brachial plexus, pleural catheters)
• sympathectomy -> another reason for a critically unwell patient to by hypotensive
• problems with coagulopathy -> epidural haematoma
• catheters over longer term -> risk of infection
• confused patients are more likely to dislodge catheters
• may fail (patient exposed to risk but no benefit)

References and Links

Textbooks and journal articles

• Liu SS, Wu CL. Effect of postoperative analgesia on major postoperative complications: a systematic update of the evidence. Anesth Analg. 2007 Mar;104(3):689-702. PMID: 17312231.
• Rigg JR, Jamrozik K, Myles PS, Silbert BS, Peyton PJ, Parsons RW, Collins KS; MASTER Anaethesia Trial Study Group. Epidural anaesthesia and analgesia and outcome of major surgery: a randomised trial. Lancet. 2002 Apr 13;359(9314):1276-82. PMID: 11965272.